Hallo,

Wie kan mij wat meer vertellen ivm de G64/21 versnellingsbak van de 993 carrera 4.

Dit zijn gegevens die mij reeds opvielen tijdens mijn zoektocht op het web:

1. Hier staat hij niet tussen, is dit toeval?:

Porsche 930 76-77 (930 early 4 speed)
Porsche 930 78-88 (930 late 4 speed)
Porsche 911 87-89 (G50/01)
Porsche 930 89 only (G50/50)
Porsche 964 C2 90-94 (G50/03)
Porsche 964 C4 90-94 (G64/00)
Porsche 965 C2 Turbo 91-94 (G50/52)
Porsche 993 C2 95-98 (G50/20)
Porsche 993 C4 95-98 (G64/20)
Porsche 993 Turbo AWD 96-98 (G64/51)

2. The /21 gearbox is very similar to the Turbo's /51 version in terms of gear ratios:

/21:

1st - 3.818
2nd - 2.150
3rd - 1.560
4th - 1.242
5th - 1.024
6th - 0.820

/51 (worldwide):

1st - 3.818
2nd - 2.150
3rd - 1.560
4th - 1.212
5th - 0.937
6th - 0.750

3. As some of you already know, Porsche introduced the normally aspirated 993 in 1994 with a relatively close-ratio gearbox called the G50/21 (G64/21 for AWD). However, cars bound for the United States, Austria and Switzerland, had to have the G50 (G64)/20 gearbox with taller and slightly more spaced gears to meet fuel economy and noise restrictions in those countries. As of MY 1997, Porsche installed only the /20 gearbox on all normally aspirated 993's worldwide.

Recently, I had a G64/21 installed in my '96 C4S. The gears from 2nd to 6th are all shorter and 2nd is slightly closer to 1st while the gaps between all other gears are also slightly smaller. This combination of ratios allows much better acceleration throughout the rpm range of the engine. Previously, I drove around town in 3rd and barely used 4th. Now, I find myself mostly in 4th and 5th while on the freeway 6th can finally be used at legal speeds without lugging the engine. I never used 6th before because it did not accelerate at all from just about any rpm. With the shorter 6th, one can stomp on the gas from 2200 rpm and the car goes.
On the track and in tight turns, I always looked for the "right" gear between 2nd and 3rd the former being too short and the latter too tall. I expect the new shorter 3rd will be more adequate in such situations. The 1.024 fifth will also be very useful on long straights coming out of turns such as at Willow Springs.

Alvast bedankt voor de nuttige info
Jack-in-the-box